Susceptibility mapping as a means to visualize veins and quantify oxygen saturation

J Magn Reson Imaging. 2010 Sep;32(3):663-76. doi: 10.1002/jmri.22276.


Purpose: To create an orientation-independent, 3D reconstruction of the veins in the brain using susceptibility mapping.

Materials and methods: High-resolution, high-pass filtered phase images usually used for susceptibility weighted imaging (SWI) were used as a source for local magnetic field behavior. These images were subsequently postprocessed using an inverse procedure to generate susceptibility maps of the veins. Regularization and interpolation of the data in k-space of the phase images were used to reduce reconstruction artifacts. To understand the effects of artifacts, and to fine-tune the methodology, simulations of blood vessels were performed with and without noise.

Results: With sufficient resolution, major veins in the brain could be visualized with this approach. The usual geometry-dependent phase dipole effects are removed by this processing, leaving basically images of the veins. Different sized vessels show a different level of contrast depending on their partial volume effects. Vessels that are 8 mm or 16 mm in size show quantitative values expected for normal oxygen saturation levels. Smaller vessels show smaller values due to errors in the methodology and due to partial volume effects. Larger vessels show a bias toward a reduced susceptibility approaching 90% of the expected value. Limitations of the method and artifacts related to different sources of errors are demonstrated.

Conclusion: Susceptibility maps can successfully create venograms of the brain with varying levels of contrast-to-noise depending on the size of the vessel. Partial volume effects render this approach more useful as an imaging tool or a visualization tool, although certain larger vessels have measured susceptibilities close to expected values associated with normal blood oxygen saturation levels.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Algorithms
  • Brain / blood supply*
  • Brain Mapping / methods*
  • Humans
  • Image Enhancement / methods
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Angiography / methods*
  • Models, Theoretical
  • Oximetry
  • Oxygen Consumption / physiology
  • Veins / physiology*